The Bureau of Labor Statistics has
info on employment costs. Social Security and Medicare are 5.9% of labor costs (there's more to labor costs than wages). But notice that health insurance is 7.1% of employee compensation. This becomes taxable under the FairTax (paid by the employer) so, while businesses may save 5.9% on SS/M, they are paying and addition 2.1% of the employee compensation in FairTax. The net savings on employee compensation is only 3.8%.
Wild assertions based on gross conceptual errors.
Health insurance like all other products and services has federal embedded taxes in its cost and price structure. The FairTax is merely replacing these embedded taxes, so don’t insinuate that the FairTax is an additional tax, it is a repackaged federal tax in transparent form.
The rest of your calculations carry forward this error.